Method of preparing an insulated negative buoyancy flow line

Abstract

Method of preparing an insulated negative buoyancy conduit wherein a jacket is placed around the conduit and an insulating material comprising a porous filler and a resin-forming composition is positioned in the annulus between the jacket and the conduit.

What is claimed is: 
     
       1. A method of preparing an insulated negative buoyancy flow line comprising: a. positioning a section of jacket concentrically about a section of flow line to provide an annulus therebetween, the section of flow line extending beyond each end of the section of jacket;   b. positioning a first solid spacer element in the annulus at one end thereof to close one end of the annulus;   c. positioning a second solid spacer element in the other end of the annulus to close the other end of the annulus, said second solid spacer element being adapted for insertion of a pair of hollow probes therethrough into said annulus;   d. inserting a pair of hollow probes through said second solid spacer element with the outlets thereof positioned near the closed one end of the annulus;   e. filling the annulus with porous filler particles by injecting the particles through one of said hollow probes into said annulus and withdrawing said probe as the annulus is filled;   f. injecting a settable resin-forming composition through the other of said hollow probes into the annulus around the porous filler particles and withdrawing said other probe as the resin-forming composition is injected; and   g. allowing the resin forming composition to set.   
     
     
       2. The method of claim 1 wherein said porous filler particles are hollow microspheres. 
     
     
       3. The method of claim 1 wherein said porous filler particles are rigid predominantly closed-cell foam particles. 
     
     
       4. The method of claim 1 wherein said porous filler particles are polystrene expanded bead foam particles having a diameter of 1/16 inch, the settable resin-forming composition is a catalyzed settable epoxy resin composition, and the jacket is a cement jacket. 
     
     
       5. The process of claim 4 wherein the section of flow line, after the resin-forming composition has set, is joined to another section of insulated flow line and the portion of said flow line sections extending beyond the jacket sections thereof is covered by short sections of insulating material.